wlan adhoc mode crash

[John Hay]

On Tue, Dec 01, 2009 at 04:40:56PM +0100, Paul B Mahol wrote:
> On 12/1/09, John Hay <jhay at meraka.org.za> wrote:
> > Hi,
> >
> > I'm not sure if this is the best list.
> >
> > I'm trying to get our Avila (arm) boards with atheros wireless cards
> > upgraded from 7.2 to 8.0. We use adhoc mode and I get a panic in
> > ieee80211_getcapinfo() because the chan pointer is 0xffff which seems
> > to mean IEEE80211_CHAN_ANY in other places. So the question is, should
> > ieee80211_getcapinfo() never be called with chan being 0xffff or should
> > it know how to handle that case?
> 
> IEEE80211_CHAN_ANY is there to mean no channel is selected, so you can not call
> getcapinfo with such argument.

I finally got back to this. I can panic an Avila ARM and a Wrap i386
board (8-stable based) with this sequence:

/sbin/ifconfig wlan0 create wlandev ath0 wlanmode adhoc
/sbin/ifconfig wlan0 country ZA
/sbin/ifconfig wlan0 up
/sbin/ifconfig wlan0 channel 132 ssid ptabb 

They do not panic immediately, but a few seconds later. It happens
inside ieee80211_getcapinfo() and chan is 0xffff.

Those ifconfig lines basically mimic the following rc.conf lines:

wlans_ath0="wlan0"
create_args_wlan0="wlanmode adhoc"
ifconfig_wlan0="country ZA"
ifconfig_wlan0_alias0="channel 132 ssid ptabb"
#ipv6_prefix_wlan0="fd9c:6829:597c:10"

If one move the "ifconfig wlan0 up" line down to after setting the
channel and ssid, the panic does not happen.

John
-- 
John Hay -- jhay at meraka.csir.co.za / jhay at FreeBSD.org